A smart card may dissipate different amounts of power according to the instructions it is executing. Switching current drawn by the transistors of a smart card may vary along the logic path for different instructions it executes. It is possible to gain knowledge of internal algorithms being used in smart cards simply by examining its power traces. Advanced statistical techniques including differential power analysis, can detect small power variations in processing devices to identify individual bits. This can result in secret key information being extracted from smart cards during the execution of computation. If sensitive information such as a password is transmitted during computation, the stored password may become compromised.